The proposed research will examine the cognitive processes involved in the formation and testing of hypotheses about social behavior. We will examine the relations between people's responses to specific items of information and the hypotheses they form on the basis of that information from three perspectives. First, we will study the effects of confirmations and disconfirmations on subjects' belief in their hypotheses. Subjects will form hypotheses about the causal determinants of behavior, and then they will find that these hypotheses are frequently disconfirmed. We will measure the effects of a) pre- experimental beliefs, b) factors present while the hypothesis is being formed, and c) factors present while the hypothesis is being tested in order to identify the major determinants of hypothesis maintenance despite disconfirmations. Second, we will focus on the effects of hypotheses on responses to specific items of information. We will examine the effects of trait information on memory for a person's behaviors and the effects of the theme of a conversation on memory for the specific details of that conversation. Finally, we will consider whether subjects' inferences vary depending on the specificity of the information they have received and the information they expect to receive. We will compare inferences based on descriptions of behaviors with inferences based on personality trait information.